<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Pgsql.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Db_Adapter_Pdo_Abstract
 */
require_once 'Zend/Db/Adapter/Pdo/Abstract.php';

/**
 * Class for connecting to PostgreSQL databases and performing common operations.
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Db_Adapter_Pdo_Pgsql extends Zend_Db_Adapter_Pdo_Abstract {

    /**
     * PDO type.
     * @var string
     */
    protected $_pdoType = 'pgsql';

    /**
     * Keys are UPPERCASE SQL datatypes or the constants
     * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
     * Values are:
     * 0 = 32-bit integer
     * 1 = 64-bit integer
     * 2 = float or decimal
     * @var array Associative array of datatypes to values 0, 1, or 2.
     */
    protected $_numericDataTypes = array(Zend_Db::INT_TYPE => Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE, Zend_Db::FLOAT_TYPE => Zend_Db::FLOAT_TYPE, 'INTEGER' => Zend_Db::INT_TYPE, 'SERIAL' => Zend_Db::INT_TYPE, 'SMALLINT' => Zend_Db::INT_TYPE, 'BIGINT' => Zend_Db::BIGINT_TYPE, 'BIGSERIAL' => Zend_Db::BIGINT_TYPE, 'DECIMAL' => Zend_Db::FLOAT_TYPE, 'DOUBLE PRECISION' => Zend_Db::FLOAT_TYPE, 'NUMERIC' => Zend_Db::FLOAT_TYPE, 'REAL' => Zend_Db::FLOAT_TYPE);

    /**
     * Creates a PDO object and connects to the database.
     * @return void
     * @throws Zend_Db_Adapter_Exception
     */
    protected function _connect () {
        if ($this -> _connection) {
            return;
        }
        parent::_connect ();
        if ( ! empty ($this -> _config['charset'])) {
            $sql = "SET NAMES '" . $this -> _config['charset'] . "'";
            $this -> _connection -> exec ($sql);
        }
    }

    /**
     * Returns a list of the tables in the database.
     * @return array
     */
    public function listTables () {
        // @todo use a better query with joins instead of subqueries
        $sql = "SELECT c.relname AS table_name " . "FROM pg_class c, pg_user u " . "WHERE c.relowner = u.usesysid AND c.relkind = 'r' " . "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) " . "AND c.relname !~ '^(pg_|sql_)' " . "UNION " . "SELECT c.relname AS table_name " . "FROM pg_class c " . "WHERE c.relkind = 'r' " . "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) " . "AND NOT EXISTS (SELECT 1 FROM pg_user WHERE usesysid = c.relowner) " . "AND c.relname !~ '^pg_'";
        return $this -> fetchCol ($sql);
    }

    /**
     * Returns the column descriptions for a table.
     * The return value is an associative array keyed by the column name,
     * as returned by the RDBMS.
     * The value of each array element is an associative array
     * with the following keys:
     * SCHEMA_NAME => string; name of database or schema
     * TABLE_NAME => string;
     * COLUMN_NAME => string; column name
     * COLUMN_POSITION => number; ordinal position of column in table
     * DATA_TYPE => string; SQL datatype name of column
     * DEFAULT => string; default expression of column, null if none
     * NULLABLE => boolean; true if column can have nulls
     * LENGTH => number; length of CHAR/VARCHAR
     * SCALE => number; scale of NUMERIC/DECIMAL
     * PRECISION => number; precision of NUMERIC/DECIMAL
     * UNSIGNED => boolean; unsigned property of an integer type
     * PRIMARY => boolean; true if column is part of the primary key
     * PRIMARY_POSITION => integer; position of column in primary key
     * IDENTITY => integer; true if column is auto-generated with unique values
     * @todo Discover integer unsigned property.
     * @param string $tableName
     * @param string $schemaName OPTIONAL
     * @return array
     */
    public function describeTable ($tableName, $schemaName = null) {
        $sql = "SELECT
                a.attnum,
                n.nspname,
                c.relname,
                a.attname AS colname,
                t.typname AS type,
                a.atttypmod,
                FORMAT_TYPE(a.atttypid, a.atttypmod) AS complete_type,
                d.adsrc AS default_value,
                a.attnotnull AS notnull,
                a.attlen AS length,
                co.contype,
                ARRAY_TO_STRING(co.conkey, ',') AS conkey
            FROM pg_attribute AS a
                JOIN pg_class AS c ON a.attrelid = c.oid
                JOIN pg_namespace AS n ON c.relnamespace = n.oid
                JOIN pg_type AS t ON a.atttypid = t.oid
                LEFT OUTER JOIN pg_constraint AS co ON (co.conrelid = c.oid
                    AND a.attnum = ANY(co.conkey) AND co.contype = 'p')
                LEFT OUTER JOIN pg_attrdef AS d ON d.adrelid = c.oid AND d.adnum = a.attnum
            WHERE a.attnum > 0 AND c.relname = " . $this -> quote ($tableName);
        if ($schemaName) {
            $sql .= " AND n.nspname = " . $this -> quote ($schemaName);
        }
        $sql .= ' ORDER BY a.attnum';
        $stmt = $this -> query ($sql);
        // Use FETCH_NUM so we are not dependent on the CASE attribute of the PDO connection
        $result = $stmt -> fetchAll (Zend_Db::FETCH_NUM);
        $attnum = 0;
        $nspname = 1;
        $relname = 2;
        $colname = 3;
        $type = 4;
        $atttypemod = 5;
        $complete_type = 6;
        $default_value = 7;
        $notnull = 8;
        $length = 9;
        $contype = 10;
        $conkey = 11;
        $desc = array();
        foreach ($result as $key => $row) {
            $defaultValue = $row[$default_value];
            if ($row[$type] == 'varchar' || $row[$type] == 'bpchar') {
                if (preg_match ('/character(?: varying)?(?:\((\d+)\))?/', $row[$complete_type], $matches)) {
                    if (isset ($matches[1])) {
                        $row[$length] = $matches[1];
                    } else {
                        $row[$length] = null; // unlimited
                    }
                }
                if (preg_match ("/^'(.*?)'::(?:character varying|bpchar)$/", $defaultValue, $matches)) {
                    $defaultValue = $matches[1];
                }
            }
            list ($primary, $primaryPosition, $identity) = array(false, null, false);
            if ($row[$contype] == 'p') {
                $primary = true;
                $primaryPosition = array_search ($row[$attnum], explode (',', $row[$conkey])) + 1;
                $identity = (bool) (preg_match ('/^nextval/', $row[$default_value]));
            }
            $desc[$this -> foldCase ($row[$colname])] = array('SCHEMA_NAME' => $this -> foldCase ($row[$nspname]), 'TABLE_NAME' => $this -> foldCase ($row[$relname]), 'COLUMN_NAME' => $this -> foldCase ($row[$colname]), 'COLUMN_POSITION' => $row[$attnum], 'DATA_TYPE' => $row[$type], 'DEFAULT' => $defaultValue, 'NULLABLE' => (bool) ($row[$notnull] != 't'), 'LENGTH' => $row[$length], 'SCALE' => null, // @todo
'PRECISION' => null, // @todo
'UNSIGNED' => null, // @todo
'PRIMARY' => $primary, 'PRIMARY_POSITION' => $primaryPosition, 'IDENTITY' => $identity);
        }
        return $desc;
    }

    /**
     * Adds an adapter-specific LIMIT clause to the SELECT statement.
     * @param string $sql
     * @param integer $count
     * @param integer $offset OPTIONAL
     * @return string
     */
    public function limit ($sql, $count, $offset = 0) {
        $count = intval ($count);
        if ($count <= 0) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("LIMIT argument count=$count is not valid");
        }
        $offset = intval ($offset);
        if ($offset < 0) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("LIMIT argument offset=$offset is not valid");
        }
        $sql .= " LIMIT $count";
        if ($offset > 0) {
            $sql .= " OFFSET $offset";
        }
        return $sql;
    }

    /**
     * Return the most recent value from the specified sequence in the database.
     * This is supported only on RDBMS brands that support sequences
     * (e.g. Oracle, PostgreSQL, DB2). Other RDBMS brands return null.
     * @param string $sequenceName
     * @return string
     */
    public function lastSequenceId ($sequenceName) {
        $this -> _connect ();
        $sequenceName = str_replace ($this -> getQuoteIdentifierSymbol (), '', (string) $sequenceName);
        $value = $this -> fetchOne ("SELECT CURRVAL(" . $this -> quote ($this -> quoteIdentifier ($sequenceName, true)) . ")");
        return $value;
    }

    /**
     * Generate a new value from the specified sequence in the database, and return it.
     * This is supported only on RDBMS brands that support sequences
     * (e.g. Oracle, PostgreSQL, DB2). Other RDBMS brands return null.
     * @param string $sequenceName
     * @return string
     */
    public function nextSequenceId ($sequenceName) {
        $this -> _connect ();
        $sequenceName = str_replace ($this -> getQuoteIdentifierSymbol (), '', (string) $sequenceName);
        $value = $this -> fetchOne ("SELECT NEXTVAL(" . $this -> quote ($this -> quoteIdentifier ($sequenceName, true)) . ")");
        return $value;
    }

    /**
     * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT column.
     * As a convention, on RDBMS brands that support sequences
     * (e.g. Oracle, PostgreSQL, DB2), this method forms the name of a sequence
     * from the arguments and returns the last id generated by that sequence.
     * On RDBMS brands that support IDENTITY/AUTOINCREMENT columns, this method
     * returns the last value generated for such a column, and the table name
     * argument is disregarded.
     * @param string $tableName OPTIONAL Name of table.
     * @param string $primaryKey OPTIONAL Name of primary key column.
     * @return string
     */
    public function lastInsertId ($tableName = null, $primaryKey = null) {
        if ($tableName !== null) {
            $sequenceName = $tableName;
            if ($primaryKey) {
                $sequenceName .= "_$primaryKey";
            }
            $sequenceName .= '_seq';
            return $this -> lastSequenceId ($sequenceName);
        }
        return $this -> _connection -> lastInsertId ($tableName);
    }

}
